BOOK REVIEW: Brain Rules by John Medina

As the title suggests, this is a book of guidance about how to get the most out of one’s mental life. Medina goes a mile wide, looking at twelve areas in which one can improve the performance of one’s brain, including: exercise, attention, memory, sleep, stress management, sensory integration, and visual acuity. It also has chapters that explain how evolution and gender affect the way in which one’s brain operates.

After an Introduction that sets up the premise of the book, there are twelve chapters. The first chapter explores the well-documented connection between exercise and mental performance, and offers insight into what type of exercise has been shown to be most helpful to the brain. The second chapter pertains to our brain’s evolutionary history. The conscious mind housed in the cortex is but the top floor of a multi-story enterprise, and understanding this has important ramifications for how one gets the most out of one’s brain. Chapter 3 explores the way brains are wired, which turns out to be flexibly and diversely. By flexibly, I mean that brains can be rewired by way of what is called neuroplasticity on the proviso that neurons that fire together wire together. By diversely, I mean that each individual’s brain is a bit different, and these differences can explain how someone gifted in one domain may be an idiot in other aspects of life. The next chapter deals with attention and explains why humans suck at multi-tasking (despite thinking they are the bomb) and why an extended ability to concentrate is essential to success.

The next two chapters both deal with memory, but with different types of memory—each having its own unique considerations. The first, chapter five, describes the peculiarities of short-term memory, that part of the memory that can hold a finite amount of data points at the forefront of our minds for a limited period. Chapter six deals with long-term memory, the part that holds vast stockpiles of information for extended periods (sometimes across a lifetime) but with lower fidelity and accuracy than we generally believe. While the rule offered for both forms of memory is simple—i.e. repetition is key—there is much to consider in the details. For starters, there are many other ways to divide up memory other than with respect to the short-term / long-term dichotomy (e.g. procedural v declarative) and differences in the way these types of memory work affect how they are both optimized.

The influence of sleep on mental performance is the subject of chapter seven. There is a vast pile of research on this subject, including a number of famous cases of extreme sleep deprivation—some of which are touched upon herein. It’s true that there is a great deal of variation in how people sleep (e.g. morning v non-morning people, and those who can power nap and those who can’t.) However, one thing remains unambiguous and that’s that we need sleep and must have full cycles of it in order to not suffer mental degradation. Chapter 8 is about how stress can kill mental performance. Of course, not all stress is the same. When one feels in control, short bursts of stress can be just the motivator one needs, but when feeling out of control stress can become crippling.

Chapters 9 and 10 are both about the senses. The first, nine, explains how one can obtain synergistic outcomes in a multi-sensory environment, and the second focuses on vision—arguably our most dominant sense. Our sensory experience is much more a product of the brain (and much less a pure representation of the outside world) than we tend to believe.

Chapter 11 reports on the gender differences that have been discovered with respect to brains. Before anyone lights a torch or sharpens a pitchfork, this isn’t the old “boys do math and girls do language” line. The differences are more nuanced, and it’s not clear in every case that the differences matter—or how. E.g. Men have bigger amygdala (involved in emotional response) and produce serotonin more quickly. While it’s not clear that these differences make a big difference, it’s know that men and women use their amygdala differently in times of stress, men activate the right amygdala and tend to remember more of the gist of events while women trip the left and remember more emotional details. The last chapter is about our human proclivity to explore, but it focuses heavily on infancy and childhood, during which the world is novel and the impulse to explore is at its height.

Each chapter ends with a summary box that both restates the rule and offers a few bullet points of key takeaway lessons, which may either be more specific guidance or summary of relevant research findings. There aren’t many functional graphics—by functional I mean as opposed to the ornamental drawings used throughout. I only remember one brain drawing. However, the reason for the dearth of graphics may be that there is a link to a 45 minute video that one can access, and the publisher probably thought that was a much more useful way to impart graphic information. It should also be noted that in the Kindle edition that I have, the references are also on-line.

I found this book to be useful. As I mentioned, it’s a broad overview. One can get books that dive more deeply into all of the topics addressed. But this is a nice mix of popular science and self-help. It’s readable, and the summaries and concise statement of rules help make the content stick more effectively.

I’d recommend this book for those who are seeking a book that covers a lot of ground, and which offers practical guidance as to how to put scientific discoveries on the brain into use in one’s own life.